MACRO language
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Built on top of SCAT, this is a language that represents purely
concatenative code generators (macros).
This code is parameterized in target.ss, which provides 2 SCAT
functions 'compile' and 'literal' that produce postponed target
function calls and literal data loads.
It can be used all by itself for a purely concatenative Forth-like
language (The PURRR concatenative macro subset), or extended with
syntax (parsing words) to represent Forth code.